The United Nations warned Thursday that violence is spreading across Ivory Coast, citing nearly two dozen rapes in the country's west and one case where a political opponent was sexually tortured.

Local U.N. human rights chief Simon Munzu said Thursday that 23 women have been raped in the last week in western Ivory Coast, where 16,000 people have taken refuge since the disputed Nov. 28presidential runoff vote. Another 29,000 people have fled across the border to Liberia. (…)

Munzu said Thursday that security forces loyal to Gbagbo had used sexual torture techniques on at least one Ouattara supporter, following a raid on Ouattara's party headquarters two weeks ago in which 63 people were arrested.

"This young man was sodomized by eight members of the Republican Guard who wanted to extract information about his fellow members of the (pro-Ouattara) RHDP," Munzu said.

There was no immediate reaction from Gbagbo's camp, though his spokesman has previously denied allegations that security forces were behind cases of abduction and torture.

The U.N. voted Wednesday to beef up its peacekeeping force in the country by sending 2,000 more troops, bringing the total to almost 13,000 in this volatile West African country.

Gbagbo's government reacted harshly to the announcement Thursday, reiterating its claim that the U.N. has overstepped its mandate and is no longer impartial.

Despite increasing attacks on U.N. patrols, Munzu downplayed the impact of the reinforcements that include two attack helicopters.

"Adding 2,000 more troops to an existing mission in (Ivory Coast) is nothing spectacular and we would like to hope that all parties concerned will see it like that and not put things out of context."

Ouattara benefits from international recognition and has begun replacing Ivory Coast's ambassadors abroad. However, Gbagbo retains control of security forces, the civil service, and the exports of oil and cocoa.

Gbagbo and his allies have been targeted with a travel ban by the European Union and the United States. Switzerland joined them on Wednesday, freezing the assets of Gbagbo and his entourage.

The latest attempt at negotiation failed Wednesday when African Union mediator Raila Odinga cut short his second visit, saying Gbagbo hasn't been keeping his promises.The West African bloc of countries known as ECOWAS has threatened to oust Gbagbo by force if negotiations fail, but has set no deadline for such an intervention.